Eat a Mediterranean diet, which encourages plenty of fruits, vegetables and nuts; so-called "healthy fats" such as olive oil; low-glycemic carbohydrates such as garlic and onions; and cold-water fish such as salmon and halibut. It will protect your brain while it helps your heart, says Sinatra, who is also a board-certified cardiologist.

Look into new "smart drugs," such as Centrophenoxine, Piracetam, Vinpocetine, Hydergine and Eldepryl, which have been shown in some tests to decrease declines in memory.

The U.S. Food and Drug Administration has not approved the so-called smart drugs for improving learning and memory, and data are mixed about whether the products, which can sometimes be found in health food stores and in other cases must be imported, have beneficial effects on brain functioning. The strongest evidence seems to support their usefulness for people with diseases such as Alzheimer's or traumatic brain injury.

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For the majority of people, Sinatra says, "The most important thing is not to take smart drugs, but to be smart about insidious environmental toxins." His examples of such toxins include electromagnetic fields ("kids talking on the cell phone for six, seven hours a day is a disaster"), excessive amounts of alcohol, and the street drug ecstasy.

Smart drugs aside, an approved Alzheimer drug has lately shown benefits for people who show no signs of dementia. In a new study, the drug Donepezil improved the ability of healthy pilots aged 30 to 70 to perform complicated tasks during a simulated flight.

Today: pilots. Tomorrow: the rest of us who need to take a test or remember an important phone number. A prediction from the Alliance for Aging Research's Daniel Perry: Within five to 10 years, a magical memory pill will be discovered that will be "one of the great joys of the baby boomers."